Our Earth Science class would like to know the change in ocean depths as you approach the research area? We have been visiting your site daily. Good luck in your research.

From: Chris Mann, Wenatchee High School

Hello Chris and the rest of Ms. Reichmann’s class:
Glad to hear you are following along! We expect to leave Mauritius this evening and head out to the Central Indian Ridge. Once we cross over the platform on which Mauritius sits, we shall be over an area of the ocean called the “abyssal plain” which is typically fairly flat and has water depths of over 4000 m. As we approach the mountains of the Central Indian Ridge, the water depths will shoal up to about 2200 m. If you look at the Research Area map on your Dive and Discover poster, you will see the there is a valley with depths of about 3500 m that runs between the mountains. We will be working along the walls of this rift valley.

Hope you will continue to follow along!
Susan Humphris

Can you please tell me what the word FAUNA means?

From,
Tanya Lake

Hello Tanya:
The word “fauna” is derived from a Latin word and is used to refer to animal life, especially in contrast to “flora” which is used to refer to plant life. I am sure you have heard the phrase “flora and fauna” -- that means plant and animal life.

Keep Diving and Discovering!
Susan Humphris

Hello.
My name is Devo, and I go to the Nantucket High School. I was curious as to how creatures make their way to the hydrothermal vents- do you think they have some sort of mechanism that directs them there....? I’m really curious about this.

Thanks
From: Devo Tubbs

Dear Devo:
You ask an extremely interesting question. Since vents were first discovered, scientists have believed that the larvae (young hatched from adult eggs) of vent animals disperse from one vent site to another by currents. We know that shallow water larvae have behaviors that they use to help direct them in the currents to find a suitable place to settle and grow. They also use cues (or signs) -- for example, certain chemicals in the water or a certain type of rock on the seafloor -- that tell them when it is a good time to settle and become an adult. However, we are not able to directly test if larvae react to different cues because (i) it is very difficult to find animal larvae (vent or non-vent) in the deep sea, and (ii) we are unable to keep larvae alive in our laboratories (we can not yet create the deep-sea environment in the lab.

Several vent biologists are currently trying to keep larvae alive by placing eggs into pressure chambers that mimic the great pressure in the deep-sea. Only larvae from one vent animal, the giant tube worm Riftia pachyptila, have been kept alive in these chambers. The larvae lived for 40 days! Larvae living for 40 days in the ocean might travel hundreds of kilometers in deep-sea currents until reaching a suitable place to live near a hydrothermal vent.

If you could create a deep-sea environment in your classroom, how would you test whether a chemical signal (like hydrogen sulfide) or type of rock were influencing how larvae might be directed to a vent site?

Tim Shank

Thanks for writing back. This sounds like a very interesting expedition. I have some more questions for you. Why do you want to know what’s at the vents? Why do you want to know if the animals found at the different vents are related? Why do you want to know how they got down there? And why do you want to see if they can explain how life evolved on earth? What will benefit by knowing the answers to the questions you hope to answer on this expedition?

From: Kaitlyn Layfield

Hi Kaitlyn:
Thanks for your very good questions. Rather than answering each one, I will try to give you an overview of why scientists are interested in vents. Twenty-five years ago, we didn’t even know vents existed on planet Earth -- and yet we live here! Since then, over 400 new organisms have been described. Many people think that we know all there is to know about Earth, but the discovery of hydrothermal vents shows that there is still much to learn. Scientists are curious human beings, and we want to understand what shapes the place we live, what lives on Earth, and how different organisms are related.

Who will benefit? Well, many of the advances we make in improving our daily lives and in technology depend on basic research that provides an understanding of our environment. It is hard to predict what the outcome will be, but I will give you a couple of examples. First, since the discovery of hydrothermal vents and the mineral deposits that form at them, we have a better understanding of how some types of ore deposits on land form. We mine those ore deposits for metals such as copper and zinc, so we need to know better how to explore for them. Second, the enzymes from the bacteria that live at hydrothermal vents are now being used in the biotechnology industry for all sorts of manipulations of DNA.